For anyone interested in mathematics/science, the Mahler lectures for 2009 and 2011 are now available as pdf’s.
They vary in complexity, but most have a wide audience such as Terence Tao’s “The Cosmic Distance Ladder”, which I attended in person when held at UWA.
a good read and certainly very easy to follow for a layman like myself. many of the observations made certainly seem obvious however i admire the lateral thinking these great minds employed to solve the problem at hand.